The present invention generally relates to a relay module for use with a series of interconnected hazardous condition detectors. More specifically, the present invention relates to a relay module that is interconnected with a series of hazardous condition detectors such that the relay module can selectively respond to the detection of a first sensed condition, a second sensed condition, or both.
Hazardous condition detection systems are well known and are required by building codes of most communities. Typical hazardous condition detection alarm systems include alarms that respond to the detection of either smoke or carbon monoxide (CO) within the building, or both. Such systems may also be configured to include alarms that respond to heat or the detection of flammable vapors.
Since the early detection of a hazardous condition and the notification of the occupant as soon as possible has proven to be the best possible way to provide the building occupants with the required time to exit the building, many building codes, including the U.S. National Fire Code, require the hazardous condition detectors located throughout a building to be electrically connected to each other in a system such that when any of the detectors is activated, all of the detectors sound an alarm. Through the interconnection of the individual detectors, a sleeping occupant on the second floor of a building will be awakened by the detection of the hazardous condition anywhere throughout the dwelling, such as the basement. To ensure that smoke detectors throughout the home or building can be connected, most manufacturers create detectors that are compatible with a three-wire interconnection. In a standard three-wire interconnection, the first wire is utilized to supply voltage to the detector, the second wire is used as the return, and the third wire provides the ability for the interconnected detectors to provide signals between the detectors.
Since the series of interconnected hazardous condition detectors can include detectors of different varieties, such as a smoke alarm unit, a carbon monoxide alarm unit or a combination smoke and carbon monoxide alarm unit, the signals sent along the interconnect line must vary depending upon the type of hazardous condition detected. For example, if one of the interconnected hazardous condition detectors detects the presence of smoke, it is required by UL Standards that the interconnected detectors each generate only the standard horn pattern for the detection of smoke, which is different than the horn pattern used for the detection of carbon monoxide.
The Schmurr U.S. Pat. No. 6,611,204, the disclosure of which is incorporated herein by reference, teaches a system and communication method that allows the interconnected hazardous condition detectors to receive the interconnect signal and generate the proper temporal pattern based upon the type of hazardous condition detected as indicated by the interconnect signal. The system taught by the Schmurr '204 patent allows various types of hazardous condition detectors to be interconnected and properly operate to generate the proper audible alarm signal.
Although the interconnected hazardous condition detection alarm system taught by the Schmurr '204 patent has proven to be effective in relaying audible alarms throughout a household, it is desirable to provide additional audible or visual indications or actions based upon the detection of the hazardous condition. Presently, relay modules, such as the Firex Model No. 0499, exist that connect a relay device to a series of interconnected smoke alarms. Upon the detection of a smoke condition by one of the detectors, the interconnect signal on the interconnect line causes a relay within the relay module to move from a first position to a second position. Various auxiliary devices, such as strobe lights, sirens, exit signs, warning lights, fire doors, exhaust fans or other indicators can be connected to the relay such that when the smoke condition is detected, the relay moves to the second position and activates each of these auxiliary devices.
Although the currently available relay modules function well to respond to the detection of a smoke condition within a series of interconnected smoke alarms, the currently available relay modules are unable to respond to either a detected first condition or a detected second condition, or both, in a connected system of different types of hazardous condition detectors. Therefore, a need exists for a relay module that can be configured to respond to either a first sensed condition, a second sensed condition or both to provide activation of auxiliary devices connected to the relay module.